On Sunday, April 15, 2007 EPA R10 ER Duty Officer was notified of Mercury release at a residential property within the city limits of Yakima. Apparently, approximately 8 months ago a one liter bottle of mercury was either found or provided to two youths, 12 and 16 years old, at the residence. The youths and at least four other children in the neighborhood played with the mercury over the ensuing period. The 16-year-old was admitted to a hospital in Seattle late last week, being diagnosed with mercury poisoning. The Yakima Fire Department, Yakima Health District and Washington Department of Ecology responded to the spill. With the assistance of a response contractor, Ecology cleaned up visible mercury along the uncontrolled access street and sidewalk. Spilled mercury was thought to still be in the fenced yard and the home and concern exists over other potential areas of significantly hazardous contamination, including other homes, schools, vehicles, etc. Although the fire department made a preliminary inquiry in the neighborhood, it was not comprehensive or conclusive. EPA assistance was requested to lend technical advise and possible cleanup. OSC Kathy Parker and two EPA START3 contractors were dispatched early Monday morning. Additional resources including an OSC - Greg Weigel, 2 STARTS and 4 ERRS contractors were mobilized to determine the extent of contamination and address remaining unsecured contamination. Mercury vapor screening found high levels of mercury in the home of the boy suffering from mercury poisoning and in the neighboring home. Hot spots were identified in the yards of the two homes, and adjacent sidewalk. EPA initiated additional assessment and cleanup.
5/1/2007: Heated and ventilated the house at 1013 S 6th St. overnight. Removed and discarded bathroom sink and toilet and remaining plumbing pipes. Continued removing remaining flooring and some subflooring from the house as well as switch plates and outlet covers to facilitate vacuuming all the wall voids. Amended action memo signed mid-day by Dan Opalski, EPA ECL Division Director, raising the removal action ceiling to $390,000. Emailed the amended action memo to the Yakima Valley library for public posting. Hand excavated crawl space soil with high levels of mercury under the kitchen sink and the back door. Taped off all vents into the house and crawl space then heated and ventilated the house and crawl space overnight. Met with the owner to discuss the schedule for replacement tasks and relocation issues. ERRS started looking for a short-term apartment rental for the family to reduce on-going relocation costs. ERRS TCLP results for 5 roll-offs indicated the waste is below the TCLP threshold and can go to a Subtitle D landfill. ERRS sampled the remaining 6 roll-offs for TCLP mercury. ERRS Removal Manager Jason Coury was replaced by Brian Chernick.
5/2/2007: After heating and ventilating overnight, START checked the mercury levels of the remaining flooring using a narrow grid pattern and identified more areas where flooring needed to be removed. The walls, wall voids and chandelier all read ambient levels. ERRS removed contaminated sections of flooring from the laundry room, hallway and kitchen. START checked the mercury levels in the storage box of cleaned items and found levels around 2300 ng/m3. The street in front of the door to the storage box was found to have traces of mercury in the gutter opposite the house. The higher than background readings in the storage box may be due to vapor blowing in from the street rather than a source in the box. The OSC contacted neighbors to get cars moved so the weed burner could be used to clean the street gutter. START then checked the gutter on the same side of the street as the house and found that there was still measurable mercury in the gutter from the corner of LaSalle and 6th St. to the first set of mail boxes. ERRS used the weed burner to heat the gutter in all affected areas. The owner of 1013 came by in the morning to explain she had to leave town and may be away for a month or more. The OSC and ERRS RM spoke with the tenant in 1011-1/2 about replacement of carpet and took measurements of the floor.
5/3/2007: START found the concentration of mercury in the house air had reduced overnight. They found a few more hotspots in the flooring and ERRS removed a couple linear inches of sheetrock and studs in the wall at floor level between the laundry room and kitchen. START experimented with washing the curb with muriatic acid because the weed burner was not effective and volatilized mercury into the breathing zone. Except for the RM, ERRS and the OSC demobilized. START stayed on and heated and ventilated the house overnight and then started collecting 8 hour air samples at midnight.
5/4/2007: START finished collecting the air samples and demobilized, taking the samples to the lab in Tacoma. The RM waited for the Phillips truck to arrive to collect the drum of elemental mercury waste and then demobilized.
Transport waste to landfill.
Develop cleaning method and clean street gutter and curb.
After getting air samples results back on 5/10/2007, determine if cleanup in the house at 1013 is completed.
Get Yakima Health District clearance to reoccupy the house.
Replace building components:
EPA plans to replace the carpeting and has already replaced the bathroom Ptrap in the house at 1011-1/2 S. 6th St. The building components and plumbing fixtures EPA has removed and plans to replace in the house at 1013 S. 6th St. are:
760 sf vapor barrier, floor insulation, underlayment and a combination of carpet and vinyl flooring
200 sf subflooring
20 lf kitchen cabinet bases
20 lf kitchen counters and counter decking
Sewer vents and plumbing pipes from laundry room, bathroom sink, tub, kitchen sink and dishwasher to sewer connection
Stairs at back door
Exterior sliding glass door and frame
Two vinyl windows (3'x4')
Three exterior window and door frames
Bathroom sink and faucet,
Kitchen sink, faucet and cabinet
Toilet
Kitchen sink and faucet
Patch lower edges and replace sheetrock in some areas
Replace several sections of studs at threshold between laundry room and kitchen
Neighborhood informational distribution program.
|
